Electrical apparatus



Nov. 1, 1932.,- E. B. NEwlLL ELECTRICAL Afmwrus Filed oct. 17, 1930' I u!! d INVENT? I Uhu # ATTORNEYS Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE EDWARD B. N EWILL, OF DAYTON, OHIO, .ASBIGNOB T GENERAL IOTOBS RADIO CORPORATION, 0F DAYTON, OHIO, A COBPOBATTOH 0I' OHIO mnc'rnrcnn APPARATUS AApplica'ldim Med October 17, 1980. Serial No. 489,818.

This invention relates to a control mechanism for a radio receiver and more particularly to the adjusting means for setting the indicator indicating the signal received or the like.

An object of this invention is to provide an adjusting means for the control that is reliable, easily constructed, easily adjusted and cheap to manufacture. This has been accomplished by providing an adjustable impedance mechanism, an indicating mechenisin :tor indicating the settin of said impedence, e screw threaded shanJ for driving one oi seid mechanisms, e rotary member if, screw threededly engagin said elicit, seid rotery member rotating with the shaft'. and moving in cooperation said other noechenisni, en adjusting ineens ici' edjinsting seid rotery member on said elicit, seid means including e loclr nut carried by seid elicit, and e wesh T heving a detent engaging e hey wey so es to be nonroteteble with respect to seid shaft, seid wesh-er being mounted intermediate seid rotery member 13 and said loclr nut so es 'to prevent reletive rotary movement between seid rotfiry member and said shaft when the lool-r nut is tightened and' so es to permit relative nime-n rnent between seid rotary member and seid shaft when loosened.

Further objects and advantages ci the present invention will he apparent iiroin the following description, reference being had to the accompanying drawing, wherein c. preferred embodiment or" one forni othe present invention is clearly shown.

ln the drawing:

l represents e front view oi a radio chassis.

Fig. 2 is a sectional view taken on line 2 2 o Fig. l and drawn to an enlarged scale.

Fig. 3 is a fragmentary sectional view taken on the line 3 3 of Fig. l.

1'. Fig. 4 discloses an enlarged fragmentary sectional view, taken on the line 4 4 0i Fig: 1'.

ig. 5 is a sectional view taken on the line 5 5 of Fi g. 2.

Fig. 6 is another modification. l

ldesired, tbreederlly engages the threaded Referring to the drawing, a chassis 2O .provides one bearing (not shown) for a. shaft 22. A second bearing 2i is supported by a bracket 26 which is secured to the front wall of the chassis. Referring more particularly to Fig. 2 e. control knob 28 of any suitable mouiding material, as for instance bakelite, is rigidly connected to the free end of the shalt 2 by e. set screw 3G, threaded into the knob 28 and e bushing 32 which is moulded therein and telres up moet of the back pressure of the set screw 38.

A pulley 3ieither e. smooth peripheral snrigece 3@ or: e. groove suri'ece, il?

535 portion 38 of the shalt 25E. Besteed ci be ing threaded on the shaft 22 the pniley could shut a stop on the shaft 22 suoli es e ccilniJ 23 or the lille disclosed in Fig. A. washer 16, having hey-hire extension 42 tliat projects into en snrinl slot 'or key-wa ifi in the shaft 22; is placed between a hn' 35 oi the pulley 3i and e loclr nnt 46. enible cable ctteehed to the i nliey 34 b any suitable interloelring means not shown ,e wound around. 1imlley 34 in several layers is ,nsssed over a grooved idler policy 50..

The cable in receives enough tension .from e. spiral spring 52, connecting both ends ci seid cable 48, to tightly engage the pulleys 3d ne and 50. l

Referring more particularlyto Figs. end 4, an indicating'niember 54 is slidably mounted upon a guide bar 56 which is fastened to the chassis 20 by screws 58. This indicating member 54, travelling in front of e scale 6G, indicating various wave lengths or frequencies of radio signals or the like, is held in proper position by a leaf spring 62, which is constantly held under tension by projecting the same between a stud 64, fastened to the indicating member 54, and a felt pad or the like, which slides upon the inner surface of guide bar 56. This felt pad 65 is crimped twice, so as to provide two extensions 66 and 67, each of which is sewed Vtogether and project on each `'side of a U-shaped middle portion ,of the leaf spring 62 so as to hold the felt pad in position. This indicating member 54 100 is connected with the driving cable 48 at 68 in an suitable manner.

It is obvious that manual turning of knob 28 in either direction causes indicating member 54 to slide upon the guide bar 56 in proper direction without any lost motion between the knob 28 and said indicating member 54.

Referring more particularly now to Figs. 2 and 3, the shaft 22.also carries a second ulley of any suitable diameter secure the shaft 22 by a pin 72 or the like. A flexible driving cable 74 is wound around the pulley 70 in several convolutions and suitably attached thereto. The cable 74 also passes over guide pulleys 76 and 78 and is attached to a drum 80 by a spring 84, which has one end engaging a loop of the cable 74 and the other end fixed to a stud' 86 in the drum 80. A spring 77 connects both free ends of the cable 74, giving the driving cable 74 the necessary tension. The shaft 82 has ixedly attached thereto a gang condenser 83 that may beiadjusted by the drum fixedly attached to the shaft 82. lInstead of gang condensers other impedances, suchv as variable inductances or resistances that either tune the circuit or adjust the circuit so as to change either thedquality or the quantity output may be use Constructive circumstances make it necessary to lead the cable 74 through the frame of the chassis 2O at 71 and 73.

, It is now obvious that manually turning the knob 28 causes the drum 80 to turn without practically any lost motion between the said knob and the drum 80.

While a specific embodiment of this invention is herein disclosed' and described; the

reason for having a washer 40 with the said key-like extension 42 will now be explained.

. The washer 40 interposed between the pulley 34 and the lock nut 46 does not allow these members to turn in unison upon the shaft as long as the lock nut is tight, for the reason that the washer 40 can not rotate on the shaft 22 in that the extension 42 is located in the slot 44. Itis therefore obvious that only the axial component of the tightened nut 46 is transmitted to the pulley 34 thereby preventing its rotation.-

From the foregoing structure it can be readily seen that when the indicator does not point to the particular frequency or wave.

length to which the condenser is turned', the pointer 54 may be adjusted by loosening nut 46, then rotating the pulley 34 either clockwise or counterclockwise on the shaft 22 as needed to set the indicator 54. The nut 46 is then tightened so as to lock the pulley 34 in a relatively fixed relation with respect to thev shaft 22. This provides dependable` eflicient, simple and cheap adjusting means for properly indexing the pointer or indicator. In

stead of being used with a slidable indicator` the same type of adjusting mechanism may be used with a rotar dia or another indicating mechanism. nstead of a cable drive any other suitable drive may be used within the scope of this invention.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other ,forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A control for a radio receiver comprising in combination, an adjustable impedance mechanism, an indicating mechanism for indicatin the settin of said impedance, a screw t readed sha t for driving one of said mechanisms, said shaft having an axial key- Way, a rotary member screw threadedly engagin said shaft, said rotary member rotating with the shaft and moving in coo eration with said other mechanism, and adjusting means for adjusting said rotary member on said shaft, said means including a lock nut carried by said shaft, and a washer having a detent engagin said key-way soV as to be non-rotatable wit respect to said shaft, said washer being mounted interm'ediate said rotary member and said lock nut so as to prevent relative rotary movement between said rotary member and said shaft when the lock nut is tightened and permits a relative movement between said rotary member and said shaft when loosened so as yto permit adjustment of the relative position of the indicating mechanism with respect to the setting of the impedance mechanism.

2. A control for a radio receiver comprising in combination an adjustable impedance mechanism; an indicating mechanism for indicating the setting of the impedance mechanism; and connecting means for connecting said mechanisms, said connecting means including a screw threaded shaft driving one of said mechanisms, a rotary member rotatably mounted on said shaft and limited in axial movement thereon, said rotary member actuating said other mechanism and a lock nut threaded on said shaft for locking said rotary member on said shaft when the indicating mechanism has been adjusted with respect to said impedance mechanism whereby relative movement between the shaft and the rotary member is prevented.

3. A control for a radio receiver comprising in combination an adjustable impedance mechanism; an indicating mechanism for indicating the setting of the impedance mechanism; a control; and connecting means for connccti the control to each of said mechanisms, said connecting means including a screw threaded shaft having a key-way; a rotary member rotatably mounted on said shaft for adjustment and axially limited in movement thereon, said member actuating said other mechanism; a lock nut threaded on said shaft and a washer having a. detent eng said key-way mounted intermediate saulm nut and said rotatable member so that said washer is non-rotatably mounted on said shaft but reely movable axially whereby as the lock nut is tightened said rotary member is prevented from rotating with respect to said'shaft.

In testimony whereof I hereto aix my signature.

EDWARD B. NEWILL. 

